used to flow into the nerves, being no longer kept | ment of the dignity, without its attendant inconopen by the frequency of the spirits, shut of them-veniences; while, on the other hand, the king selves; thus the nerves, wanting a new supply of who supposes himself degraded, feels all the misspirits, become lax, and unfit to convey any im- ery of his fallen fortune, without trying to find pression to the brain. All this, however, is ex- the comforts of his humble situation. Thus, by plaining a very great obscurity by somewhat more day, both states have their peculiar distresses: obscure; leaving, therefore, those spirits to open but, by night, the exalted beggar is perfectly and shut the entrances to the brain, let us be blessed, and the king completely miserable." contented with simply enumerating the effects of All this, however, is rather fanciful than just; sleep upon the human constitution. the pleasure dreams can give us, seldom reaches to our waking pitch of happiness: the mind often, in the midst of its highest visionary satisfactions, demands of itself, whether it does not owe them to a dream; and frequently awakes with the reply. But it is seldom, except in cases of the highest delight, or the most extreme uneasiness, that the mind has power thus to disengage itself from the dominion of fancy. In the ordinary course of its operations, it submits to those numberless fantastic images that succeed each other, and which, like many of our waking thoughts, are generally forgotten. Of these, however, if any, by their oddity, or their continuance, affect us strongly, they are then remembered; and there have been some who felt their impressions so In sleep, the whole nervous frame is relaxed, while the heart and the lungs seem more forcibly exerted. This fuller circulation produces also a swelling of the muscles, as they always find who sleep with ligatures on any part of their body. This increased circulation also, may be considered as a kind of exercise, which is continued through the frame; and by this, the perspiration becomes more copious, although the appetite for food is entirely taken away. Too much sleep dulls the apprehension, weakens the memory, and unfits the body for labour. On the contrary, sleep too much abridged, emaciates the frame, produces melancholy, and consumes the constitution. It requires some care, therefore, to regulate the quantity of sleep, and just to take as much as will completely restore nature, without oppress-strongly, as to mistake them for realities, and to ing it. The poor, as Otway says, sleep little; forced by their situation, to lengthen out their labour to their necessities, they have but a short interval for this pleasing refreshment; and I have ever been of opinion, that bodily labour demands a less quantity of sleep than mental. Labourers and artisans are generally satisfied with about seven hours; but I have known some scholars who usually slept nine, and perceived their faculties no way impaired by oversleeping. rank them among the past actions of their lives. There are others upon whom dreams seem to have a very different effect, and who, without seeming to remember their impressions the next morning, have yet shown, by their actions during sleep, that they were very powerfully impelled by their dominion. We have numberless instances of such persons who, while asleep, have performed many of the ordinary duties to which they had been accustomed when waking; and, with a ridiculous industry, have completed by night, what they failed doing by day. We are told, in the German Ephemerides, of a young student, who being enjoined a severe exercise by his tutor, went to bed, despairing of accomplishing it. The next morning awaking, to his great surprise, he found the task fairly written out, and finished in his own handwriting. He was at first, as the account has it, induced to ascribe this strange production to the operations of an infernal agent; but his tutor, willing to examine the affair to the bottom, set him another exercise, still more severe than the former, and took precautions to observe his conduct the whole night. The young gentleman, upon being so severely tasked, felt the same inquietude that he had done on the former occasion; went to bed gloomy and pensive, pondering on the next day's duty, and Sleep is indeed, to some, a very agreeable after some time fell asleep. But shortly after, period of their existence and it has been a ques- his tutor, who continued to observe him from a tion in the schools, Which was most happy, the place that was concealed, was surprised to see man who was a beggar by night, and a king by him get up, and very deliberately go to the table, day; or he who was a beggar by day, and a king where he took out pen, ink, and paper, drew himby night? It is given in favour of the nightly self a chair, and sat very methodically to thinkmonarch, by him who first started the questioning: it seems, that his being asleep, only served For the dream," says he, "gives the full enjoy- to strengthen the powers of his imagination; for The famous Philip Barrettiere, who was considered as a prodigy of learning at the age of fourteen, was known to sleep regularly twelve hours in the twenty-four; the extreme activity of his mind when awake, in some measure called for an adequate alternation of repose; and, I am apt to think, that when students stint themselves in this particular, they lessen the waking powers of the imagination, and weaken its most strenuous exertions. Animals that seldom think, as was said, can very easily dispense with sleep; and of men, such as think least, will, very probably, be satisfied with the smallest share. A life of study, it is well known, unfits the body for receiving this gentle refreshment; the approaches of sleep are driven off by thinking: when, therefore, it comes at last, we should not be too ready to interrupt its continuance. he very quickly and easily went through the task assigned him; put his chair aside, and then returned to bed to take out the rest of his nap. What credit we are to give to this account, I will not pretend to determine; but this may be said, that the book from whence it is taken, has some good marks of veracity; for it is very learned, and very dull; and is written in a country noted, if not for truth, at least for want of invention.1 The ridiculous story of Arlotto is well known, who has had a volume written, containing a narrative of the actions of his life, not one of which was performed while he was awake. He was an Italian Franciscan friar, extremely rigid in his manners, and remarkably devout and learned in his daily conversation. By night, however, and during his sleep, he played a very different character from what he did by day, and was often detected in very atrocious crimes. He was at one time detected in actually attempting a rape, and did not awake till the next morning, when he was surprised to find himself in the hands of justice. His brothers of the convent often watched him while he went very deliberately into the chapel, and there attempted to commit sacrilege. They sometimes permitted him to carry the chalice and the vestments away into his own chamber, and the next morning amused themselves at the poor man's consternation for what he had done. But of all his sleeping transgressions, that was the most ridiculous, in which he was called to pray for the soul of a person departed. Arlotto, after having very devoutly performed his duty, retired to a chamber, which was shown him, to rest; but he had no sooner fallen asleep, than he began to reflect that the dead body had got a ring upon one of the fingers, which might be useful to him: accordingly, with a pious resolution of stealing it, he went down, undressed as he was, into a room full of women, and, with great composure, endeavoured to seize the ring. The consequence was, that he was taken before the inquisition for witchcraft; and the poor creature had like to have been condemned, till his peculiar character accidentally came to be known: however, he was ordered to remain for the rest of life in his own convent, and upon no account whatsoever to stir abroad. What are we to say to such actions as these? or how account for this operation of the mind in dreaming 25 It should seem that the imagina 4 This hit at the Germans, it need scarcely be said, does not now apply to them, as, since Goldsmith's time, they have proved themselves, by their literary works, to be a people of the most fertile fancy.-ED. 5 Although sleep implies the perfect repose of the organs of sensation and of motion, some of these organs persist in their activity; which obliges us to acknowledge intermediate states between sleep and waking, real mixed situations, which belong, more or less, to one or to the other. Let us suppose, for instance, that the imagination reproduces, in the tion, by day, as well as by night, is always employed; and that often against our wills, it intrudes, where it is least commanded or desired. While awake, and in health, this busy principle cannot much delude us: it may build castles in the air, and raise a thousand phantoms before us; but we have every one of the senses alive to bear testimony to its falsehood. Our eyes show us that the prospect is not present: our hearing and our touch depose against its reality; and our taste and smelling are equally vigilant in detecting the imposture. Reason, therefore, at once gives judgment upon the cause, and the vagrant intruder, Imagination, is imprisoned, or banished from the mind. But in sleep it is otherwise; having, as much as possible, put our senses from their duty, having closed the eyes from seeing, and the ears, taste, and smelling, from their peculiar functions, and having diminished even the touch itself, by all the arts of softness, the imagination is then left to riot at large, and to lead the understanding without an opposer. Every incursive idea then becomes a reality; and the mind, not having one power that can prove the illusion, takes them for truths. As in madness, the senses, from struggling with the imagination, are at length forced to submit; so, in sleep, they seem for a while soothed into the like submission: the smallest violence exerted upon any one of them, however, rouses all the rest in their mutual defence; and the imagination, that had for a while told its thousand falsehoods, is totally driven away, or only permitted to pass under the custody of such as are every moment ready to detect its imposition. CHAP. VII. OF SEEING.1 "HAVING mentioned the senses as correcting the errors of the imagination, and, as forcing it, in brain, sensations it has formerly known, the intellect works, associates, and combines ideas, often discordant, and sometimes natural, brings forth monsters, horrible, or fantastic, or ridiculous; raises joy, hope, grief, surprise, or terror; and all these fancies, all these emotions, are recollected more or less distinctly, when we are again awake, so as to allow no doubt but that the brain has been really in action, during the repose of the organs of sense and emotion. Dreams is the name given to these phenomena. Sometimes we speak in sleep, and this brings us a little nearer to the state of waking, since to the action of the brain is added that of the organs of speech. Finally, all the relative functions are capable of action, excepting the outward senses. The brain acts, and determines the action of the organs of motion or speech, only in consequence of former impressions; and this state, which differs from waking only by the inaction of the senses, is called somnambulism.Richeraud. 1 This chapter is taken from Mr. Buffon. I be lieve the reader will readily excuse any apology; and some measure to bring us just information, it will naturally follow that we should examine the nature of those senses themselves: we shall thus be enabled to see how far they also impose on us, and how far they contribute to correct each other. Let it be observed, however, that in this we are neither giving a treatise of optics nor phonics, but a history of our own perceptions: and to those we chiefly confine ourselves." The eyes very soon begin to be formed in the human embryo, and in the chicken also. Of all the parts which the animal has double, the eyes are produced the soonest, and appear the most prominent. It is true, indeed, that in viviparous animals, and particularly in man, they are not so large in proportion, at first, as in the oviparous kinds; nevertheless they are more speedily developed, when they begin to appear, than any other parts of the body. It is the same with the organ of hearing; the little bones that compose the internal parts of the ear are entirely formed before the other bones, though much larger, have acquired any part of their growth or solidity. Hence it appears, that those parts of the body which are furnished with the greatest quantity of nerves, are the first in forming. Thus the brain and the spinal-marrow are the first seen begun in the embryo; and, in general, it may be said, that wherever the nerves go, or send their branches in great numbers, there the parts are soonest begun, and the most completely finished. If we examine the eyes of a child some hours, or even some days after its birth, it will be easily discerned that it as yet makes no use of them. The humour of the organ not having acquired a sufficient consistence, the rays of light strike but confusedly upon the retina, or expansion of nerves at the back of the eye. It is not till about a month after they are born that children fix them upon objects; for, before that time, they turn them indiscriminately everywhere, without appearing to be affected by any. At six or seven weeks old they plainly discover a choice in the objects of their attention; they fix their eyes upon the most brilliant colours, and seem peculiarly desirous of turning them towards the light. Hitherto, however, they only seem to fortify the organ for seeing distinctly; but they have still many illusions to correct. The first great error in vision is, that the eye inverts every object: and it in reality appears to the child, until the touch has served to undeceive it, turned upside down. A second error in vision is, that every object is seen double. The same object forms itself distinctly upon each eye; and is consequently seen twice. This error, also, can only be corrected by the touch; and although, in reality, every object we see appears inverted and double, yet the judgment and perhaps, may wish that I had taken this liberty much more frequently. What I add is marked, as in a former instance, with inverted commas. habit have so often corrected the sense, that we no longer submit to its imposition, but see every object in its just position, the very instant it appears. Were we, therefore, deprived of feeling, our eyes would not only misrepresent the situation, but also the number, of all things around us. To convince us that we see objects inverted, we have only to observe the manner in which images are represented, coming through a small hole in a darkened room. If such a small hole be made in a dark room, so that no light can come in but through it, all the objects without will be painted on the wall behind, but in an inverted position, their heads downwards. For as all the rays which pass from the different parts of the object without, cannot enter the hole in the same extent which they had in leaving the object; since, if so, they would require the aperture to be as large as the object; and, as each part and every point of the object sends forth the image of itself on every side, and the rays which form these images pass from all points of the object as from so many centres, so such only can pass through the small aperture as come in opposite directions. Thus the little aperture becomes a centre for the entire object; through which the rays from the upper parts as well as from the lower parts of it, pass in converging directions; and, consequently, they must cross each other, in the central point, and thus paint the objects behind upon the wall, in an inverted position. It is in like manner, easy to conceive, that we see all objects double, whatever our present sensations may seem to tell us to the contrary. For to convince us of this, we have only to compare the situation of any one object on shutting one eye, and then compare the same situation by shutting the other. If, for instance, we hold up a finger and shut the right eye, we shall find it hide a certain part of the room; if again re-shutting the other eye, we shall find that part of the room visible, and the finger seeming to cover a part of the room that had been visible before. If we open both eyes, however, the part covered will appear to lie between the two extremes. But the truth is, we see the object our finger had covered, one image of it to the right, and the other to the left; but, from habit, suppose that we see but one image placed between both; our sense of feeling having corrected the error of sight. And thus, also, if instead of two eyes, we had two hundred, we should, at first, fancy the objects increased in proportion, until one sense had corrected the errors of another, "The having two eyes might thus be said to be rather an inconvenience than a benefit; since one eye would answer the purposes of sight as well, and be less liable to illusion. But it is otherwise; two eyes greatly contribute, if not to distinct, at least to extensive vision. When an object is placed at a moderate distance, by the means of both eyes 2 Leonardo da Vinci. objects in such situations as we have not had sufficient experience to correct the errors of the eye; if, for instance, we look at men from the top of a high steeple, they, in that case, appear very much diminished, as we have not had a habit of correcting the sense in that position. we see a larger share of it than we possibly could with one, the right eye seeing a greater portion of its right side, and the left eye of its correspondent side. Thus both eyes, in some measure, see round the object; and it is this that gives it, in nature, that bold relievo, or swelling, with which they appear; and which no painting, how exquisite soever, can attain to. The painter must be contented with shading on a flat surface; but the eyes, in observing nature, do not behold the shad-ity which cannot be disputed. Mr. Cheselden having only, but a part of the figure also, that lies behind these very shadings, which give it that swelling which painters so ardently desire, but can never fully imitate. | "There is another defect, which either of the eyes taken singly would have, but which is corrected, by having the organ double. In either eye there is a point, which has no vision whatsoever so that if one of them only is employed in seeing, there is a part of the object to which it is always totally blind. This is that part of the optic nerve where its vein and artery run; which being insensible, that point of the object that is painted there must continue unseen. To be convinced of this we have only to try a very easy experiment. If we take three black patches, and stick them upon a white wall, about a foot distant from each other, each about as high as the eye that is to observe them; then retiring six or seven feet back, and shutting one eye, by trying for some time, we shall find, that while we distinctly behold the black spots that are to the right and left, that which is in the middle remains totally unseen. Or, in other words, when we bring that part of the eye where the optic artery runs, to fall upon the object, it will then become invisible. This defect, however, in either eye, is always corrected by both, since the part of the object that is unseen by one, will be very distinctly perceived by the other." Beside the former defects, we can have no idea of distances from the sight without the help of touch. Naturally every object we see appears to be within our eyes; and a child, who has as yet made but little use of the sense of feeling, must suppose that every thing it sees makes a part of itself. Such objects are only seen more or less bulky, as they approach or recede from its eyes; so that a fly that is near will appear larger than an ox at a distance. It is experience alone that can rectify this mistake; and a long aquaintance with the real size of every object quickly assures us of the distance at which it is seen. The last man in a file of soldiers appears in reality much less, perhaps ten times more diminutive, than the man next to us; however, we do not perceive this difference, but continue to think him of equal stature; for the numbers we have seen thus lessened by distance, and have found, by repeated experience, to be of the natural size when we come closer, instantly correct the sense, and every object is perceived with nearly its natural proportion. But it is otherwise, if we observe Although a small degree of reflection will serve to convince us of the truth of these positions, it may not be amiss to strengthen them by an author Al ing couched a boy of thirteen for a cataract, who had hitherto been blind, and thus at once having restored him to sight, curiously marked the progress of his mind upon that occasion. This youth, though he had been till then incapable of seeing, yet was not totally blind, but could tell day from night, as persons in his situation always may. He could also, with a strong light, distinguish black from white, and either from the vivid colour of scarlet: however he saw nothing of the form of bodies; and without a bright light, not even colours themselves. He was at first couched only in one of his eyes; and when he saw for the first time, he was so far from judging of distances, that he supposed his eye touched every object that he saw, in the same manner as his hands might be said to feel them. The objects that were most agreeable to him were such as were of plain surfaces and regular figures: though he could as yet make no judgment whatever of their different forms, nor give a reason why one pleased him more than another. though he could form some idea of colours during his state of blindness, yet that was not suffcient to direct him at present; and he could scarcely be persuaded that the colours he now saw were the same with those he had formerly conceived such erroneous ideas of. He delighted most in green; but black objects, as if giving him an idea of his former blindness, he regarded with horror. He had, as was said, no idea of forms; and was unable to distinguish one object from another, though never so different. When those things were shown him, which he had been formerly familiarized to by his feeling, he beheld them with earnestness, in order to remember them a second time; but as he had too many to recollect at once, he forgot the greatest number; and for one he could tell, after seeing, there was a thousand he was totally unacquainted with. He was very much surprised to find, that those things and persons he loved best, were not the most beautiful to be seen; and even testified displeasure in not finding his parents so handsome as he conceived them to be. It was near two months before he could find that a picture resembled a solid body. Till then he only considered it as a flat surface variously shadowed; but when he began to perceive that these kinds of shadings actually represented human beings, he then began to examine, by his touch, whether they had not the usual qualities of such bodies, and was greatly surprised to find, what he expected a very unequal surface, to be smooth and even. He was then shown a miniature-picture of his father, which was contained in his mother's watch-case, and he readily perceived the resemblance; but asked with great astonishment, how so large a face could be contained in so small a compass? It seemed as strange to him, as if a bushel was contained in a pint vessel. At first he could bear but a very small quantity of light, and he saw every object much greater than the life; but in proportion as he saw objects that were really large, he seemed to think the former were diminished; and although he knew the chamber where he was contained in the house, yet, until he saw the latter, he could not be brought to conceive how a house could be larger than a chamber. Before the operation, he had no great expectations from the pleasure he should receive from a new sense: he was only excited by the hopes of being able to read and write; he said, for instance, that he could have no greater plea sure in walking in the garden with his sight, than he had without it, for he walked there at his ease, and was acquainted with all the walks. He remarked also, with great justice, that his former blindness gave him one advantage over the rest of mankind, which was that of being able to walk in the night with confidence and security. But when he began to make use of his new sense, he seemed transported beyond measure. He said, that every new object was a new source of delight, and that his pleasure was so great as to be past expression. About a year after, he was brought to Epsom, where there is a very fine prospect, with which he seemed greatly charmed; and he called the landscape before him a new method of seeing. He was couched in the other eye, a year after the former, and the operation succeeded equally well: when he saw with both eyes, he said that objects appeared to him twice as large as when he saw but with one; however, he did not see them doubled, or, at least, he showed no marks as if he saw them so. Mr. Cheselden mentions instances of many more that were restored to sight in this manner; they all seemed to concur in their perceptions with this youth; and they all seemed particularly embarrassed in learning how to direct their eyes to the objects they wished to observe. In this manner it is that our feeling corrects the sense of seeing, and that objects which appear of very different sizes at different distances, are all reduced, by experience, to their natural standard. "But not the feeling only, but also the colour and brightness of the object, contributes, in some measure, to assist us in forming an idea of the distance at which it appears. Those which we see most strongly marked with light and shade, we readily know to be nearer than those on which the colours are more faintly 3 Mr. Buffon gives a different theory, for which I must refer the reader to the original. That I have given, I take to be easy and satisfactory enough. 3 spread, and that, in some measure, take a part of their hue from the air between us and them.Bright objects also are seen at a greater distance than such as are obscure, and, most probably, for this reason, that being less similar in colour to the air which interposes, their impressions are less effaced by it, and they continue more distinctly visible. Thus a black and distant object is not seen so far off as a bright and glittering one, and a fire by night is seen much farther off than by day." The power of seeing objects at a distance is very rarely equal in both eyes. When this inequality is in any great degree, the person so circumstanced then makes use only of one eye, shutting that which sees the least, and employing the other with all its power. And hence proceeds that awkward look which is known by the name of strabism. There are many reasons to induce us to think that such as are near-sighted see objects larger than other persons; and yet the contrary is most certainly true, for they see them less. Mr. Buffon informs us that he himself is short-sighted, and that his left eye is stronger than his right. He has very frequently experienced, upon looking at any object, such as the letters of a book, that they appear less to the weakest eye; and that when he places the book, so as that the letters appear double, the images of the left eye, which is strongest, are greater than those of the right, which is the most feeble. He has examined several others, who were in similar circumstance, and has always found that the best eye saw every object the largest. This he ascribes to habit; for nearsighted people being accustomed to come close to the object, and view but a small part of it at a time, the habit ensues, when the whole of an object is seen, and it appears less to them than to others. Infants having their eyes less than those of adults, must see objects also smaller in proportion. For the image formed on the back of the eye will be large, as the eye is capacious; and infants having it not so great, cannot have so large a picture of the object. This may be a reason also why they are unable to see so distinctly, or at such distances, as persons arrived at maturity. Old men, on the contrary, see bodies close to them very indistinctly, but bodies at a great distance from them with more precision; and this may happen from an alteration in the coats, or perhaps, humours of the eye; and not, as is supposed, from their diminution. The cornea, for instance, may become too rigid to adapt itself, and take a proper convexity for seeing minute objects; and its very flatness will be sufficient to fit it for distant vision. When we cast our eyes upon an object extremely brilliant, or when we fix and detain them too long upon the same object, the organ is hurt and fatigued, its vision becomes indistinct, and |